Are all 2 inch filter the same

[KenGee]

I got two Orion filters when I was up in Brizzy a few months ago, I finally got around to getting a filter draw (Astronomik) and guess what the filters don't fit:(. I then tried the filters on one of my 2 inch eye pieces and it don't fit on there either:mad2:.
It doesn't look like their cross threaded or anything, am I just luky/dumb:screwy: or have other people had this problem?

[Glenhuon]

I've noticed that some eyepieces have a coarser thread for filters than others. The eyepieces that came with my original 150 newtonian were like that. There is a "Standard", but not all makers follow it. I note you have a Williams scope, so its probably the filter threads that are not stanadard.

Bill

[JohnG]

I have an Orion 2" Moon Filter and found that it screws into all my 2" TeleVue eyepieces but wont screw into my TV EverBright Diagonal where I want it :shrug:, yet the Baader Filters I have screw into everything.

Cheers

[matt]

I've experienced the same.

Some of my filters screw in to my eyepieces/filter wheel etc better than others.

Could just be some variance in machining:shrug:

It's bloody annoying, though.

Whatever you do, don't force it. I've found that it can sometimes just take a few gentle efforts of screwing the filter in and out to help the process.

Sometimes the threads on either surface have blackening agent or something else which needs wearing down before things turn a little 'smoother'.

[ausastronomer]

Hi,

It's because of the paint thickness on the blackening on some of the threads is too thick and the fact that some of the tolerances on the threads are pretty tight. All 2" astronomy filters, apart from a few odd ones, use a standard 48mm x .75mm metric thread. If you get a metal workers sharp scribe and trace out the male and female threads with the scribe point, you will find they fit fine.

I can guarantee you the Orion filters are 48mm x .75, as is the TV diagonal.

Cheers,
John B

[Starkler]

Sometimes eyepieces have faulty threads too. I had one on a brand new 24mm panoptic and had to get the barrel replaced. You don't expect poor workmanship when paying Televue prices :whistle: